title: Hypodipsia discriminates progressive supranuclear palsy from other parkinsonian syndromes.
abstract: BACKGROUND
  The objective of this study was to evaluate whether the sensation of thirst differs between patients with progressive supranuclear palsy (PSP), multiple system atrophy with predominant parkinsonism (MSA-P), and Parkinson's disease (PD).
  
  
  METHODS
  We administered a standardized thirst questionnaire to age-, sex-, and stage-matched patients with probable PSP, PD, and MSA-P and healthy controls (HC), n = 15/group. In an independent cohort (n = 10/group), we provoked thirst by infusing hypertonic NaCl in age-, sex-, and stage-matched patients with PSP, PD, and MSA-P and recorded plasma osmolality and thirst (visual analog scale).
  
  
  RESULTS
  On questioning, 73% of PSP patients reported a reduced sensation of thirst (hypodipsia) compared with previous years (HC, 0%; PD, 7%; MSA-P, 7%; P < .0001). On NaCl infusion, PSP patients reported significantly lower thirst than did PD and MSA-P patients for all times from 20 to 95 minutes (P < .05). The thirst score at 25 minutes discriminated individual PSP patients well from PD and MSA-P patients.
  
  
  CONCLUSIONS
  Hypodipsia appears helpful in differentiating PSP from PD and MSA-P.
authors.affiliation: Department of Neurology, Philipps University, Marburg, Germany. stamelou@staff.uni-marburg.de
authors.forename: Maria
authors.initials: M
authors.lastname: Stamelou
authors.forename: Helena
authors.initials: H
authors.lastname: Christ
authors.forename: Alexander
authors.initials: A
authors.lastname: Reuss
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Oertel
authors.forename: Günter
authors.initials: G
authors.lastname: Höglinger
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003937:Diagnosis, Differential; D004326:Drinking / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020734:Parkinsonian Disorders / Q000150:complications* / Q000175:diagnosis*; D013223:Statistics as Topic; D013494:Supranuclear Palsy, Progressive / Q000150:complications* / Q000175:diagnosis*; D011795:Surveys and Questionnaires; D014868:Water Deprivation / Q000502:physiology